Method and apparatus for melting solid material and for dispensing the melt



June 20, 1967 R. s. ESTABROOKS 3,325,415

METHOD AND APPARATUS FOR MELTING SOLID MATERIAL NG THE MELT AND FORDISPENSI Original Filed March 15, 1965 3 Sheets-Sheet l INVENTOR Roger5. Esfobroo/rs BY fi, j.

ATTORNEY .Fune 20, 1967 R. s. ESTABROOKS 3,

METHOD AND APPARATUS FOR MELTING SOLID MATERIAL AND FOR DISPENSING THEMELT Original Filed March 15, 1965 3 Sheets-Sheet June 20, 1967 R. s.ESTABROOKS 3,326,415

METHOD AND APPARATUS FOR MELTING SOLID MATERIAL AND FOR DISPENSING THEMELT Original Filed March 15, 1965 3 Sheets-Sheet 5 United States PatentO 4 Claims. (Cl. 222-1) This invention relates to method and apparatusfor melting a solid material and thereafter dispensing it. The instantapplication is a division of pending United States application Ser. No.439,661 filed Mar. 15, 1965.

Among the objects of this invention is to provide an improved method andapparatus for melting thermoplastic or other meltable material, otherobjects and advantages being apparent from the foregoing specification.

In practicing this invention, solid thermoplastic adhesive or similarmaterial capable of being rendered fluid by means of application of heatis loaded into a melting tank where a heating element at the base of thetank causes the adhesive to liquefy. The surface of the base of the tankhas grooves and troughs formed therein which serve to increase theeffective heat transfer area of the interior of the melting tank anddirect the flow of the molten adhesive to an outlet formed on the tank.

In the accompanying drawings:

FIGURE 1 is a front elevation of the apparatus incorporating the instantinvention;

FIGURE 2 is a plan view of the apparatus incorporating the instantinvention as seen from line 22 of FIG- URE 1;

FIGURE 3 is a sectional view of the melting tank taken along the line3-3 of FIGURE 2; and

FIGURE 4 is a side elevation of the melting tank as seen from line 4-4of FIGURE 3.

Referring to FIGURE 1 a melting tank is mounted on a platform 12 themelting tank being fabricated from aluminum or other heat conductivematerial. The melting tank 10 has a base 14 upon which the solidthermoplastic adhesive 16 rests as indicated in FIGURE 3. The tank 10may be provided with a cover 18. Centrally located in the base 14 is anorifice 20 which leads into another concentric orifice 22 of a smallerdiameter, the bottom of the smaller orifice forming a valve seat whichaccommodates a ball check valve 24 (see FIGURE 3). The ball 24 isrestricted to substantially vertical motion by four pins 26 which aremounted on the underside of the base 14 and lie on the circumference ofa circle which is concentric with the orifice and the base 14. Thevertical movement of the ball 24 is accomplished by means of a float arm28 upon which the ball freely rests, the float arm being pivotallymounted with a float 30 being attached to one extremity of the float arm28 and a counter weight 32 being slidably connected to the otherextremity. The bottom of the ball 24 rests on the float arm at a pointintermediate the float arm pivot 34 and the float 30. A float chamber 36located underneath the melting tank base 14 houses the float valvemechanism 38 and receives the molten adhesive as it flows through theorifii 20 and 22 past the ball check valve 24. As the level of adhesiverises within the float chamber the float 30 will similarly rise causingthe float arm 28 to swing about the float arm pivot 34 thereby impartingan upward movement to the ball check valve 24 to thereby obstruct theorifice 22 and preclude further flow of adhesive therethrough. The levelof adhesive at which the ball check valve 24 may obstruct the orifice 22may be varied by varying the position of the counter weight 32 on thefloat arm 28.

Heat is supplied to the melting tank by means of an annular electricheating element 40 embedded in the melting tank base 14. The uppersurface 42 of the melting tank base upon which the solid adhesive restsis flat with the exception of a plurality of radial troughs 44 which areinclined downwardly from the periphery of the melting tank base 14 tothe center of the melting tank base 14 where the troughs terminate inthe larger orifice 20. There is also an annular trough 46 at theperiphery of the melting tank base 14 which is in communication with theradial troughs 44.

These troughs 44 and 46 serve a dual purpose in that they facilitate thegravitation of the molten adhesive to and through the orifii 20 and 22and that they cause a more rapid rate of melting of the solid adhesivedue to the increased surface area of the melting tank base 14.

I claim:

1. A method of melting a solid material and dispensing the resultingmelt comprising:

placing the solid material directly upon a heat conductive platformhaving a centrally located orifice, a peripheral trough disposed belowthe level of the upper surface of said platform and a plurality ofradial troughs interconnecting said peripheral trough and said orifice,said radial troughs being inclined downwardly from said peripheraltrough to said orifice;

and applying heat to said platform whereby said heat may be transferredto said solid material, thereby melting it, said melted materialgravitating to and through said orifice by means of said troughs.

2. A method of melting a solid material and dispensing the resultingmelt comprising:

placing the solid material directly upon a heat conductive platformhaving a centrally located orifice and a plurality of radial troughs,each of said radial troughs being in communication with said orifice andinclined downwardly from the periphery of said plat form to saidorifice;

and applying heat to said platform whereby said heat may be transferredto said solid material, thereby melting it, said melted materialgravitating to and through said orifice by means of said troughs.

3-. An apparatus for melting a solid material comprising:

a melting tank having a base in which is formed a centrally locatedorifice, a trough located at the periphery of said base and beingdisposed below the level of said base and a plurality of radial troughsinterconnecting said peripheral trough with said orifice, said radialtroughs being inclined downwardy from said peripheral trough to saidorifice whereby said solid material may be placed directly upon saidbase and thus be melted, said melted material gravitating towards andthrough said orifice by means of said troughs;

and means for heating said base. 7

4. An apparatus for melting and dispensing a solid material comprising:

a melting tank having a base in which is formed a centrally locatedorifice, a trough located at the periphery of said base and a pluralityof radial troughs interconnecting said peripheral trough with saidorifice, said radial troughs being inclined downwardly from saidperipheral trough to said orifice whereby said solid material may beplaced directly on said base and thus be melted, said molten materialgravitating towards and through said orifice by means of said troughs;

means for heating said base;

3 4 a chamber disposed below said base so as to form a fice to therebypreclude the flow of molten material receptacle for said molten materialas it flows therethrough until the level of said material within throughsaid orifice; said chamber recedes. a float located within said chamberand having a portion thereof disposed below said orifice, said float 5References Cited being moveable heightwise in response to a changeUNITED STATES PATENTS of level of molten material within said chamber;and 1 109 832 9/1914 Graham et a] X a valve member supported on saidportion of said float 4 4/1961 Kamborian and being moveable heightwisetherewith so as to 3011042 11/1961 Kamborian X be engageable with saidorifice in blocking and un- 10 blocking relation therewith whereby asthe level of FOREIGN PATENTS molten material rises Within said chambersaid 33 299 7 1933 France.

heightwise movement of said float may bring said valve member intoblocking relation with said Ori- RAPHAEL M. LUPO, Primary Examiner.

2. A METHOD OF MELTING A SOLID MATERIAL AND DISPENSING THE RESULTINGMELT COMPRISING: PLACING THE SOLID MATERIAL DIRECTLY UPON A HEATCONDUCTIVE PLATFORM HAVING A CENTRALLY LOCATED ORIFICE AND A PLURALITYOF RADIAL TROUGHS, EACH OF SAID RADIAL TROUGHS BEING IN COMMUNICATIONWITH SAID ORIFICE AND INCLINED DOWNWARDLY FROM THE PERIPHERY OF SAIDPLATFORM TO SAID ORIFICE; AND APPLYING HEAT TO SAID PLATFORM WHEREBYSAID HEAT MAY BE TRANSFERRED TO SAID SOLID MATERIAL, THEREBY MELTING IT,SAID MELTED MATERIAL GRAVITATING TO AND THROUGH SAID ORIFICE BY MEANS OFSAID TROUGHS.